Annulment: The legal dissolution of a marriage in which the union is voided (declared as having never occurred). "A suit for annulment presumes that there never was a valid marriage and that it should be declared void, whereas a suit for divorce presumes a valid marriage but asks that the relationship be dissolved for postnuptual causes." 2 (See also Divorce.)

Automated Classification of Medical Entities (ACME): Computer program developed by the National Center for Health Statistics that assigns one underlying cause of death based on full medical information and multiple causes of death listed on the death certificate.

Birth weight: The weight of an infant at delivery, recorded in pounds and ounces or in grams.

Cause of death: Any condition which leads to or contributes to death and is classifiable according to the tenth revision of The International Classification of Diseases (ICD-10).

Chemical induction: The process of causing an abortion by using chemical stimulus.

Childbearing years: The reproductive age span of women; conventionally defined as 15 through 44 years of age for the U.S. population.

CNM: Certified Nurse-Midwife.

Cohort: A group of individuals sharing a common demographic experience with respect to an observed period of time (e.g., individuals sharing the same birth year or years, individuals who fall in a specified age range.)

Confidence interval: The range of values that has a probability x of including the true value for the population. A 95% confidence interval includes the true value for the population 95% of the time.

Congenital anomaly: Physical, physiological, or metabolic abnormality existing before or at birth, but not necessarily detectable at birth.

Crude rate: The rate of any demographic or vital event that is based on an entire population.

Demography: The study of populations including their size, age-sex composition, distribution, density, growth, natality, mortality, nuptiality, migration, and any other characteristics which may affect these factors.

Dilation and evacuation: A surgical procedure that expands the cervical canal of the uterus (dilation) so that the surface lining of the uterine wall can be scraped (curettage).

Divorce: "Divorce is the final legal dissolution of a marriage, that is, the separation of husband and wife by a judicial decree which confers on the parties the right to civil and/or religious remarriage, according to the laws of each country." 4 (See also Annulment.)

Ethnicity: The classification of a population that shares common characteristics, such as, religion, traditions, culture, language, and tribal or national origin.

Fertility: The actual reproductive performance of an individual, couple or a population.

Fetal death (stillbirth): Death of a product of conception prior to the complete expulsion or extraction from its mother, regardless of the length of gestation. In Texas, fetal death registration is required for any fetus weighing 350 grams or more, or if the weight is unknown, a fetus aged 20 weeks or more.

General fertility rate (GFR): "The number of live births per 1,000 women age 15-44 years in a given year." 5

Gestation period: Number of completed weeks elapsed between the first day of the last normal menstrual period and the date of delivery.

Homicide: Death due to injury purposefully inflicted by other individuals (ICD-10 codes, U01-U02,X85-Y09,Y87.1), death from injuries resulting from legal intervention (homicide committed by law enforcement officers; ICD-10 codes, Y35,Y89.0).

Hysterotomy: Evacuation of the pregnancy through incision of the uterus.

ICD-10: The International Classification of Diseases, 10th edition. A system for classifying diseases and injuries developed by the World Health Organization and used worldwide to improve comparability of cause of death statistics reported from different countries. The tenth revision has been in use since January 1, 1999.

Induced termination of pregnancy (induced abortion): Any act or procedure performed after a pregnancy is medically verified with the intent to cause the termination of an intra-uterine pregnancy other than for the purpose of either the birth of a live infant or removing a dead fetus.

Infant: An individual less than one year of age.

Infant death: Death of an individual less than one year of age. Infant deaths are further classified as neonatal deaths and postneonatal deaths. (See also neonatal death and postneonatal death.)

In-migration: The process of moving into a geographic area for the purpose of taking up residence.

Intrauterine Instillation: Injecting saline or prostaglandin into the uterus to cause contractions, which expel the contents of the uterus.

Kessner Index: Method of categorizing adequacy of prenatal care, based on month of pregnancy care started, number of visits, and length of gestation. This index adjusts for the fact that women with short gestations have less time in which to make prenatal care visits.

Life expectancy: The average number of years that a person can anticipate living after a given age, usually birth. Most often based upon the current mortality experience of a population.

Life table: Statistical tool typically used to portray expectation of life at various ages. Also provides information on numbers of individuals who survive to various ages, median age at death, age-specific death rates, and the probability of dying at certain ages.

Live birth: The complete expulsion or extraction from its mother of a product of conception, irrespective of the duration of the pregnancy, which after such separation, breathes or shows any other evidence of life such as beating of the heart, pulsation of umbilical cord, or definite movement of voluntary muscles, whether or not the umbilical cord has been cut or the placenta is attached.

Live birth order: The number of children born alive to a mother, including the current child. Important in demography because the probability of having an additional child is affected by the number of children a woman has previously borne.

Low birth weight: A birth weight less than 2,500 grams or less than 5 pounds, 9 ounces.

Malignant neoplasm: A tumor having the properties of invasion and metastasis.

Maternal death: The death of a woman resulting from pregnancy or childbearing, while pregnant or within 42 days of termination of pregnancy.

MCDC: Multiple cause of death coding. (See also multiple cause of death coding.)

Medical (Nonsurgical) Abortion: Administration of medications for the purpose of inducing an abortion.

Mean: The arithmetic average of a set of values. It is calculated as the sum of the values divided by the number of values.

Median: The value in an ordered set of values above and below which there are an equal number of values; the 50th percentile.

Mode: The most frequent number in a set of numbers.

Morbidity: Refers to the occurrence of diseases in a population.

Mortality: Death as a component of population change.

Multiple causes of death: All diseases or injuries which led directly to death, or all circumstances of the accident or violence which produced the fatal injury.

Multiple cause of death coding (MCDC): Provides access to all causes of death listed on the death certificate instead of a single assigned underlying cause of death. Used by ACME for assigning underlying cause of death from full medical information on death certificates. (See also Automated Classification of Medical Entities.)

Natality: Birth as a component of population change.

Natural increase: The surplus or deficit of births relative to deaths in a population in a given time period.

Neonatal death: Death of an infant less than 28 days of age.

Neonate: An infant less than 28 days of age.

Nosology: The division of the Vital Statistics Unit that classifies, for statistical purposes, causes of deaths, based on the ICD-10; the branch of medical science that deals with classification of diseases.

Occurrence, place of: Location where a vital event took place.

Occurrence data: Data compiled by the geographic place in which the event occurred without regard to the place of residence of the individual(s) involved in the event.

Out-migration: The process of permanently moving out of a geographic area.

Perinatal: Period from 20 weeks gestation through 27 days after birth.

Plurality: Classification of the number of children born of one pregnancy. Designated as single, twin, triplet, quadruplet and so on.

Population: The total of all individuals in a given area.

Postneonatal death: Death of an infant at least 28 days of age but less than one year of age.

Postneonate: An infant at least 28 days of age but less than one year of age.

Preterm birth: Birth at less than 37 completed weeks of gestation.

Proportion: A portion of a population in relation to another portion of the population or to the population as a whole. Proportions are a special type of ratio in which the denominator always includes the numerator. (See also ratio.)

Race: A geographical population of humankind that possesses inherited distinctive physical characteristics that distinguish it from other populations.

Range: The distance between the smallest and largest numbers in a set of numbers.

Rate: The frequency of a demographic event in a specified period of time divided by the population at risk of the event.

Ratio: The relation of one population subgroup to another subgroup, or to the whole population. The denominator of a ratio may or may not include the numerator. If the denominator includes the numerator, it is a special type of ratio known as a proportion. (See also proportion.)

Remaining years of life: The expectation of life at any given age; the average number of years remaining to be lived by those surviving to that age.

Residence: The geographic area of the usual place of abode.

Residence data: Data compiled by the usual place of residence without regard to the geographic place where the event occurred. For births and fetal deaths, the mother's usual residence is used as the place of residence.

Self-identification: A method of race/ethnicity classification. This classification is derived from information provided by the parents for a birth certificate or by the informant who provided information for a death certificate.

Sharp Cutterage (dilation and curretage, D&C, or surgical curretage): A surgical procedure in which the uterine contents are removed with curette.

Standardized rate: See adjusted rate.

Statistical cut-off: Date by which records of vital events for a specific year must be received in order to be included in the statistical analyses for that year.

Statistical Significance: Used to evaluate the likelihood that chance variability may be considered an explanation for observed results. An appropriate mathematical test of statistical significance is calculated to determine the p value, which is the probability that the observed results may be due to chance alone. If the p value is less than an arbitrarily chosen value, commonly selected as 0.05, the findings are accepted as statistically significant at the 5 percent level. This indicates there is less than 5 percent probability that the observed results are due to chance alone.

Years of potential life lost (YPLL): A measure of premature mortality of Texas residents for individuals who die before age 65. "The sum of the years of life lost annually by persons who suffered early deaths." 7 (See also Years of potential life lost)